Secukinumab Inhibition of Interleukin-17A in Patients with Psoriatic Arthritis

BACKGROUND

In a phase 2 study, the inhibition of the interleukin-17A receptor improved signs and symptoms of psoriatic arthritis. We sought to evaluate the efficacy and safety of secukinumab, an anti-interleukin-17A monoclonal antibody, in such patients.

METHODS

In this double-blind, phase 3 study, 606 patients with psoriatic arthritis were randomly assigned in a 1:1:1 ratio to receive intravenous secukinumab (at a dose of 10 mg per kilogram) at weeks 0, 2, and 4, followed by subcutaneous secukinumab at a dose of either 150 mg or 75 mg every 4 weeks, or placebo. Patients in the placebo group were switched to subcutaneous secukinumab at a dose of 150 mg or 75 mg at week 16 or 24, depending on clinical response. The primary end point was the proportion of patients with an American College of Rheumatology 20 (ACR20) response at week 24, defined as a 20% improvement from baseline in the number of tender and swollen joints and at least three other important domains.

RESULTS

ACR20 response rates at week 24 were significantly higher in the group receiving secukinumab at doses of 150 mg (50.0%) and 75 mg (50.5%) than in those receiving placebo (17.3%) (P<0.001 for both comparisons with placebo). Secondary end points, including the ACR50 response and joint structural damage, were significantly better in the secukinumab groups than in the placebo group. Improvements were sustained through 52 weeks. Infections, including candida, were more common in the secukinumab groups. Throughout the study (mean secukinumab exposure, 438.5 days; mean placebo exposure, 128.5 days), four patients in the secukinumab groups had a stroke (0.6 per 100 patient-years; 95% confidence interval [CI], 0.2 to 1.5), and two had a myocardial infarction (0.3 per 100 patient-years; 95% CI, 0.0 to 1.0), as compared with no patients in the placebo group.

CONCLUSIONS

Secukinumab was more effective than placebo in patients with psoriatic arthritis, which validates interleukin-17A as a therapeutic target. Infections were more common in the secukinumab groups than in the placebo group. The study was neither large enough nor long enough to evaluate uncommon serious adverse events or the risks associated with long-term use. (Funded by Novartis Pharma; ClinicalTrials.gov number, NCT01392326.).

Overexpression of MMP13 in human osteoarthritic cartilage is associated with the SMAD-independent TGF-β signalling pathway

Introduction

In vitro and animal model of osteoarthritis (OA) studies suggest that TGF-β signalling is involved in OA, but human data is limited. We undertook this study to elucidate the role of TGF-β signalling pathway in OA by comparing the expression levels of TGFB1 and BMP2 as ligands, SMAD3 as an intracellular mediator, and MMP13 as a targeted gene between human osteoarthritic and healthy cartilage.

Methods

Human cartilage samples were collected from patients undergoing total hip/knee joint replacement surgery due to primary OA or hip fractures as controls. RNA was extracted from the cartilage tissues. Real-time quantitative PCR was performed to measure gene expression. Mann-Whitney test was utilized to compare the expression levels of TGFB1, BMP2, SMAD3 and MMP13 in human cartilage between OA cases and controls. Spearman’s rank correlation coefficient (rho) was calculated to examine the correlation between the expression levels of the four genes studied and non-parametric regression was used to adjust for covariates.

Results

A total of 32 OA cases (25 hip OA and 7 knee OA) and 21 healthy controls were included. The expression of TGFB1, SMAD3, and MMP13 were on average 70 %, 46 %, and 355 % higher, respectively, whereas the expression of BMP2 was 88 % lower, in OA-affected cartilage than that of controls (all p < 0.03), but no difference was observed between hip and knee OA (all p > 0.4). The expression of TGFB1 was correlated with the expression of SMAD3 (rho = 0.50, p = 0.003) and MMP13 (rho = 0.46, p = 0.007) in OA-affected cartilage and the significance became stronger after adjustment for age, sex, and BMI. The expression of BMP2 was negatively correlated with both TGFB1 (rho = −0.50, p = 0.02) and MMP13 (rho = −0.48, p = 0.02) in healthy cartilage, but the significance was altered after adjustment for the covariates. There was no correlation between the expression of SMAD3 and MMP13.

Conclusions

Our results demonstrate that MMP13 expression is associated with an increased expression of TGFB1 in OA-affected cartilage, possibly through SMAD-independent TGF-β pathway. Furthermore, TGF-β/SMAD3 is overactivated in OA cartilage; yet, the consequence of this overactivation remains to be established.

Secukinumab, a human anti-interleukin-17A monoclonal antibody, in patients with psoriatic arthritis (FUTURE 2): a randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

Interleukin 17A is a proinflammatory cytokine that is implicated in the pathogenesis of psoriatic arthritis. We assessed the efficacy and safety of subcutaneous secukinumab, a human anti-interleukin-17A monoclonal antibody, in patients with psoriatic arthritis.

METHODS

In this phase 3, double-blind, placebo-controlled study undertaken at 76 centres in Asia, Australia, Canada, Europe, and the USA, adults (aged ≥18 years old) with active psoriatic arthritis were randomly allocated in a 1:1:1:1 ratio with computer-generated blocks to receive subcutaneous placebo or secukinumab 300 mg, 150 mg, or 75 mg once a week from baseline and then every 4 weeks from week 4. Patients and investigators were masked to treatment assignment. The primary endpoint was the proportion of patients achieving at least 20% improvement in the American College of Rheumatology response criteria (ACR20) at week 24. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT01752634.

FINDINGS

Between April 14, and Nov 25, 2013, 397 patients were randomly assigned to receive secukinumab 300 mg (n=100), 150 mg (n=100), 75 mg (n=99), or placebo (n=98). A significantly higher proportion of patients achieved an ACR20 at week 24 with secukinumab 300 mg (54 [54%] patients; odds ratio versus placebo 6·81, 95% CI 3·42-13·56; p<0·0001), 150 mg (51 [51%] patients; 6·52, 3·25-13·08; p<0·0001), and 75 mg (29 [29%] patients; 2·32, 1·14-4·73; p=0·0399) versus placebo (15 [15%] patients). Up to week 16, the most common adverse events were upper respiratory tract infections (four [4%], eight [8%], ten [10%], and seven [7%] with secukinumab 300 mg, 150 mg, 75 mg, and placebo, respectively) and nasopharyngitis (six [6%], four [4%], six [6%], and eight [8%], respectively). Serious adverse events were reported by five (5%), one (1%), and four (4%) patients in the secukinumab 300 mg, 150 mg, and 75 mg groups, respectively, compared with two (2%) in the placebo group. No deaths were reported.

INTERPRETATION

Subcutaneous secukinumab 300 mg and 150 mg improved the signs and symptoms of psoriatic arthritis, suggesting that secukinumab is a potential future treatment option for patients with this disorder.

FUNDING

Novartis.

Genetic, Epigenetic and Pharmacogenetic Aspects of Psoriasis and Psoriatic Arthritis

There is a strong familial component to psoriatic disease as well as a complex array of genetic, immunologic, and environmental factors. The dominant genetic effect is located on chromosome 6p21.3 within the major histocompatibility complex region, accounting for one-third of genetic contribution. Genome-wide association studies (GWAS) identified additional genes, including skin barrier function, innate immune response, and adaptive immune response genes. To better understand disease susceptibility and progression requires replication in larger cohorts, fine-mapping efforts, new technologies, and functional studies of genetic variants, gene-gene interactions and gene-environmental interactions. New technologies available include next-generation sequencing, copy number variation analysis, and epigenetics.

Widespread non-additive and interaction effects within HLA loci modulate the risk of autoimmune diseases

Human leukocyte antigen (HLA) genes confer strong risk for autoimmune diseases on a log-additive scale. Here we speculated that differences in autoantigen binding repertoires between a heterozygote’s two expressed HLA variants may result in additional non-additive risk effects. We tested non-additive disease contributions of classical HLA alleles in patients and matched controls for five common autoimmune diseases: rheumatoid arthritis (RA, N_cases=5,337), type 1 diabetes (T1D, N_cases=5,567), psoriasis vulgaris (N_cases=3,089), idiopathic achalasia (N_cases=727), and celiac disease (N_cases=11,115). In four out of five diseases, we observed highly significant non-additive dominance effects (RA: P=2.5×10¹²; T1D: P=2.4×10⁻¹⁰; psoriasis: P=5.9×10⁻⁶; celiac disease: P=1.2×10⁻⁸⁷). In three of these diseases, the dominance effects were explained by interactions between specific classical HLA alleles (RA: P=1.8×10⁻³; T1D: P=8.6×10²⁷; celiac disease: P=6.0×10⁻¹⁰⁰). These interactions generally increased disease risk and explained moderate but significant fractions of phenotypic variance (RA: 1.4%, T1D: 4.0%, and celiac disease: 4.1%, beyond a simple additive model).

Private rare deletions in SEC16A and MAMDC4 may represent novel pathogenic variants in familial axial spondyloarthritis

Objective

Axial spondyloarthritis (AxSpA) represents a group of inflammatory axial diseases that share common clinical and histopathological manifestations. Ankylosing spondylitis (AS) is the best characterised subset of AxSpA, and its genetic basis has been extensively investigated. Given that genome-wide association studies account for only 25% of AS heritability, the objective of this study was to discover rare, highly penetrant genetic variants in AxSpA pathogenesis using a well-characterised, multigenerational family.

Methods

HLA-B*27 genotyping and exome sequencing was performed on DNA collected from available family members. Variant frequency was assessed by mining publically available datasets and using fragment analysis of unrelated AxSpA cases and unaffected controls. Gene expression was performed by qPCR, and protein expression was assessed by western blot analysis and immunofluorescence microscopy using patient-derived B-cell lines. Circular dichroism spectroscopy was performed to assess the impact of discovered variants on secondary structure.

Results

This is the first report identifying two rare private familial variants in a multigenerational AxSpA family, an in-frame SEC16A deletion and an out-of-frame MAMDC4 deletion. Evidence suggests the causative mechanism for SEC16A appears to be a conformational change induced by deletion of three highly conserved amino acids from the intrinsically disordered Sec16A N-terminus and RNA-mediated decay for MAMDC4.

Conclusions

The results suggest that it is the presence of rare syntenic SEC16A and MAMDC4 deletions that increases susceptibility to AxSpA in family members who carry the HLA-B*27 allele.

Enhanced meta-analysis and replication studies identify five new psoriasis susceptibility loci

Psoriasis is a chronic autoimmune disease with complex genetic architecture. Previous genome-wide association studies (GWAS) and a recent meta-analysis using Immunochip data have uncovered 36 susceptibility loci. Here, we extend our previous meta-analysis of European ancestry by refined genotype calling and imputation and by the addition of 5,033 cases and 5,707 controls. The combined analysis, consisting of over 15,000 cases and 27,000 controls, identifies five new psoriasis susceptibility loci at genome-wide significance (P<5 × 10(-8)). The newly identified signals include two that reside in intergenic regions (1q31.1 and 5p13.1) and three residing near PLCL2 (3p24.3), NFKBIZ (3q12.3) and CAMK2G (10q22.2). We further demonstrate that NFKBIZ is a TRAF3IP2-dependent target of IL-17 signalling in human skin keratinocytes, thereby functionally linking two strong candidate genes. These results further integrate the genetics and immunology of psoriasis, suggesting new avenues for functional analysis and improved therapies.

Randomized controlled trial of adalimumab in patients with nonpsoriatic peripheral spondyloarthritis

OBJECTIVE

To evaluate the efficacy and safety of adalimumab in patients with active nonpsoriatic peripheral spondyloarthritis (SpA).

METHODS

ABILITY-2 is an ongoing phase III, multicenter study of adalimumab treatment. Eligible patients age ≥18 years fulfilled the Assessment of SpondyloArthritis international Society (ASAS) classification criteria for peripheral SpA, did not have a prior diagnosis of psoriasis, psoriatic arthritis (PsA), or ankylosing spondylitis (AS), and had an inadequate response or intolerance to nonsteroidal antiinflammatory drugs (NSAIDs). Patients were randomized 1:1 to receive adalimumab 40 mg every other week or matching placebo for 12 weeks, followed by a 144-week open-label period. The primary end point was the proportion of patients achieving 40% improvement in disease activity according to the Peripheral SpA Response Criteria (PSpARC40) at week 12. This was defined as ≥40% improvement from baseline (≥20-mm absolute improvement on a visual analog scale) in patient's global assessments of disease activity and pain, and ≥40% improvement in at least one of the following features: swollen joint and tender joint counts, total enthesitis count, or dactylitis count. Adverse events were recorded throughout the study.

RESULTS

In total, 165 patients were randomized to a treatment group, of whom 81 were randomized to receive placebo and 84 to receive adalimumab. Baseline demographics and disease characteristics were generally similar between the 2 groups. At week 12, a greater proportion of patients receiving adalimumab achieved a PSpARC40 response compared to patients receiving placebo (39% versus 20%; P = 0.006). Overall, improvement in other outcomes was greater in the adalimumab group compared to the placebo group. The rates of adverse events were similar in both treatment groups.

CONCLUSION

Treatment with adalimumab ameliorated the signs and symptoms of disease and improved physical function in patients with active nonpsoriatic peripheral SpA who exhibited an inadequate response or intolerance to NSAIDs, with a safety profile consistent with that observed in patients with AS, PsA, or other immune-mediated diseases.

Genetic dissection of acute anterior uveitis reveals similarities and differences in associations observed with ankylosing spondylitis

OBJECTIVE

To use high-density genotyping to investigate the genetic associations of acute anterior uveitis (AAU) in patients with and those without ankylosing spondylitis (AS).

METHODS

We genotyped samples from 1,711 patients with AAU (either primary or combined with AS), 2,339 AS patients without AAU, and 10,000 control subjects on an Illumina Immunochip Infinium microarray. We also used data for AS patients from previous genome-wide association studies to investigate the AS risk locus ANTXR2 for its putative effect in AAU. ANTXR2 expression in mouse eyes was investigated by real-time quantitative reverse transcription-polymerase chain reaction.

RESULTS

A comparison between all patients with AAU and healthy control subjects showed strong association over HLA-B, corresponding to the HLA-B27 tag single-nucleotide polymorphism rs116488202. The association of 3 non-major histocompatibility complex loci, IL23R, the intergenic region 2p15, and ERAP1, reached genome-wide significance (P < 5 × 10(-8)). Five loci harboring the immune-related genes IL10-IL19, IL18R1-IL1R1, IL6R, the chromosome 1q32 locus harboring KIF21B, as well as the eye-related gene EYS, were also associated, reaching a suggestive level of significance (P < 5 × 10(-6)). Several previously confirmed AS associations demonstrated significant differences in effect size between AS patients with AAU and AS patients without AAU. ANTXR2 expression varied across eye compartments.

CONCLUSION

These findings of both novel AAU-specific associations and associations shared with AS demonstrate overlapping but also distinct genetic susceptibility loci for AAU and AS. The associations in IL10 and IL18R1 are shared with inflammatory bowel disease, suggesting common etiologic pathways.

Relationship Between Blood Plasma and Synovial Fluid Metabolite Concentrations in Patients with Osteoarthritis

Objective.

To investigate the relationship between plasma and synovial fluid (SF) metabolite concentrations in patients with osteoarthritis (OA).

Methods.

Blood plasma and SF samples were collected from patients with primary knee OA undergoing total knee arthroplasty. Metabolic profiling was performed by electrospray ionization tandem mass spectrometry using the AbsoluteIDQ kit. The profiling yielded 168 metabolite concentrations. Correlation analysis between SF and plasma metabolite concentrations was done on absolute concentrations as well as metabolite concentration ratios using Spearman’s rank correlation (ρ) method.

Results.

A total of 69 patients with knee OA were included, 30 men and 39 women, with an average age of 66 ± 8 years. For the absolute metabolite concentrations, the average ρ was 0.23 ± 0.13. Only 8 out of 168 metabolite concentrations had a ρ ≥ 0.45, with a p value ≤ 2.98 × 10−4, statistically significant after correcting multiple testing with the Bonferroni method. For the metabolite ratios (n = 28,056), the average ρ was 0.29 ± 0.20. There were 4018 metabolite ratios with a ρ ≥ 0.52 and a p value ≤ 1.78 × 10−6, significant after correcting multiple testing. Sex-separate analyses found no difference in ρ between men and women. Similarly, there was no difference in ρ between people younger and older than 65 years.

Conclusion.

Correlation between blood plasma and SF metabolite concentrations are modest. Metabolite ratios, which are considered proxies for enzymatic reaction rates and have higher correlations, should be considered when using blood plasma as a surrogate of SF in OA biomarker identification.

2014 Update of the Canadian Rheumatology Association/Spondyloarthritis Research Consortium of Canada Treatment Recommendations for the Management of Spondyloarthritis. Part I: Principles of the Management of Spondyloarthritis in Canada

Objective.

The Canadian Rheumatology Association (CRA) and the Spondyloarthritis Research Consortium of Canada (SPARCC) have collaborated to update the recommendations for the management of spondyloarthritis (SpA).

Methods.

A working group was assembled and consisted of the SPARCC executive committee, rheumatologist leaders from SPARCC collaborating sites, Canadian rheumatologists from across the country with an interest in SpA (both academic and community), a rheumatology trainee with an interest in SpA, an epidemiologist/health services researcher, a member of the CRA executive, a member of the CRA therapeutics committee, and a patient representative from the Canadian Spondylitis Association. An extensive review was conducted of literature published from 2007 to 2014 involving the management of SpA. The working group created draft recommendations using multiple rounds of Web-based surveys and an in-person conference. A survey was sent to the membership of the CRA to obtain an extended review that was used to finalize the recommendations.

Results.

Guidelines for the management of SpA were created. Part I focuses on the principles of management of SpA in Canada and includes 6 general management principles, 5 ethical considerations, target groups for treatment recommendations, 2 wait time recommendations, and recommendations for disease monitoring. Also included are 6 modifications for application to juvenile SpA.

Conclusion.

These recommendations were developed based on current literature and applied to a Canadian healthcare context. It is hoped that the implementation of these recommendations will promote best practices in the treatment of SpA.

2014 Update of the Canadian Rheumatology Association/Spondyloarthritis Research Consortium of Canada Treatment Recommendations for the Management of Spondyloarthritis. Part II: Specific Management Recommendations

Objective.

The Canadian Rheumatology Association (CRA) and the Spondyloarthritis Research Consortium of Canada (SPARCC) have collaborated to update the recommendations for the management of spondyloarthritis (SpA).

Methods.

A working group was assembled and consisted of the SPARCC executive committee, rheumatologist leaders from SPARCC collaborating sites, Canadian rheumatologists from across the country with an interest in SpA (both academic and community), a rheumatology trainee with an interest in SpA, an epidemiologist/health services researcher, a member of the CRA executive, a member of the CRA therapeutics committee, and a patient representative from the Canadian Spondylitis Association. An extensive review was conducted of literature published from 2007 to 2014 involving the management of SpA. The working group created draft recommendations using multiple rounds of Web-based surveys and an in-person conference.

Results.

Recommendations for the management of SpA were created. Part II: Specific Management Recommendations addresses management with nonpharmacologic methods, nonsteroidal anti-inflammatories and analgesics, disease-modifying antirheumatic drugs, antibiotics, tumor necrosis factor inhibitors, other biologic agents, and surgery. Also included are 10 modifications for application to juvenile SpA.

Conclusion.

These recommendations were developed based on current literature and applied to a Canadian healthcare context. It is hoped that implementation of these recommendations will promote best practices in the treatment of SpA.